A lightweight macOS menu bar utility that shows real-time USB-C and Thunderbolt port status. See what's connected, how fast it's running, and how much power each port is using.

Apple Silicon only (M1 and later).

• Port overview at a glance from the menu bar, with active count and total power draw
• Protocol detection for Thunderbolt 3/4/5, DisplayPort alt-mode, USB3, and USB2
• Live lane status showing exactly which lanes are carrying data and at what speed
• Power monitoring with real-time wattage, voltage, current, and a 60-second rolling graph
• Device identification including product name, vendor, serial number, and USB version
• Cable info showing cable type and USB PD revision
• Display resolution for connected monitors
• Thunderbolt capability showing max supported speed and lane width per port
• Port statistics with lifetime connection counts and error tracking
• MagSafe support with charging status and power draw

Download the latest release from the releases page, unzip, and drag WhatPort.app to your Applications folder. The app is signed and notarized by Apple.

• macOS 14.0 (Sonoma) or later
• Apple Silicon Mac (M1, M2, M3, M4, or later)

git clone https://github.com/darrylmorley/whatport.git
cd whatport
xcodebuild -scheme WhatPort -configuration Release -destination 'platform=macOS' build

The built binary will be in DerivedData. No entitlements or root access needed, all IOKit reads are unprivileged.

WhatPort reads real-time data from three IOKit service layers:

1. AppleTypeCPhy for USB-C lane state (transport protocol, power level per lane)
2. IOThunderboltPort for Thunderbolt link speed, width, and capability
3. AppleSmartBattery for power delivery data (watts, voltage, current per port)

Connection events are detected via IOKit interest notifications on IOPortTransportStateCC services for sub-second response. All state (connections, power, transports) is also polled every 3 seconds as a safety net.

Three layers, each depending only on the one below:

SwiftUI (WhatPort)  ->  Domain (WhatPortCore)  ->  IOKit (WhatPortIOKit)

• WhatPortIOKit: All IOKit C API interaction. Nothing above this layer touches C pointers or IORegistry.
• WhatPortCore: Pure Swift domain model and correlation logic. No IOKit or UI imports.
• WhatPort: SwiftUI views and formatting. No data fetching or business logic.

MIT